I am using a Sony NEX 6 with manual lenses and I am very impressed with the results so far (Contax G 28 & Zeiss 35/2 ZM). I just got a Contax 45/2 G to complement the other two lenses and I noticed right away that when I shake the lens slightly you can hear a sort of rattle inside, as if a lens element floats inside and wobbles a little. I can even push the front of the lens in just slightly, but enough to see a magnified focused image go slightly out of focus (zebra pattern starts to disappears)... Can any of you with the same lens tell me if this is normal?
I asked a couple of sellers in ebay and one of them mentioned he saw the same behavior in the copy he is selling. I'd prefer a rock solid copy but I'll keep it as long as it is normal (testing optical performance this weekend).
The G lenses aren't exactly rock solid and the wobble/rattle was present in all of my G lenses but they all performed exemplary.
When you are pushing in the front lens do you actually mean that you push in the entire lens helicoid by pushing on the front lens? A front lens that can be pushed in seems like there would be something wrong with it.
I don't have any of my G lenses anymore so I can't go all maracas on them but as far as I can remember the build was good - though with a little rattle from the mechanism - but no loose front lenses.
All my G lenses (28/35/45/90) rattle with the G45/2 rattling the most.I remember that 21/.2.8 and 35-70 behaved the same way.By pushing the front element ,as kosmoskatten said already, the whole helicoid assembly is moving,so there is a little play there as well.
that's normal, it's the lens design. contax g lenses have a big spring in them that fits around the helicoid pushing the optical part outward. this applies enough force to hold the optics at the proper location during normal shooting but not to prevent wobble when you shake it or push on it.
i believe this design was used so that they could use a loose helicoid for faster AF without having trouble with focus slippage. just another example of AF lenses always being poorer built than manual focus.
